2003 CTS Code P2176?

Hey guys, i've owned my CTS for about 2 weeks now, 264,000kms (165,000 miles) paid $7,000 for it pretty sure I got a good deal lol. Anyways, a cuple nights ago, I "opened 'er up" to see what it can do. Quick little car in Sport mode :lol: I touched the redline going into second and third (but never went into the red) and I only did it once. This morning I got into my car to find the Check Engine light on. I plugged it into my code reader and it came up as "P2176: Trottle Actuator Control System - Idle Position Not Learned" It is idling a bit high too. I took it for a 20 minute drive to work and seemed OK (idling at around 1100 - a bit high) Then started it up after work and it was normal. I came home and the car was idling around 2200! I let it run for around 2 minutes or so and it went back down to normal. I shut it off and came out 2 hours later and went to start it and all I got was a click. Everything was working fine but interior lights seemed dim so I boosted it and fired right up. Drove it for 10 minutes and the voltage reading on the radio went from 14.2 down to around 13.5. I got home and pulled the Positive cable off the battery and the car till ran but the reading was jumping from around 13.2 to 14.0. Connected the cable back up and rent back to around 13.5. Shut it off and it started right back up again. I'm just wondering if maybe this has something to do with the idle acting up? Like maybe the car is trying to turn the alternator faster to correct the low reading? It should be reading around 14.2 if i'm not wrong.

Basically all I want to know is how to correct this P2176 code, or I hope I don't have to take it in :shakehead I'll try a new battery but I doubt it will fix the idle problem. Only had the car for 2 weeks! I guess the saying is true, you get what you pay for lol.

Thanks in advance guys!

Theres nothing wrong with the idle usually all V6 cars idle at a pretty high rpm thats only when the car is cold when it warms up it will drop down again.

2200 is not normal. That is too high. Check your throttle positioning sensor.